To meet a requirement imposed by a user on a data service, an operator not only upgrades a cellular network, but also introduces a WLAN (wireless local area network) and the like, to relieve data traffic pressure, so that a wireless access network gradually becomes heterogeneous. In a heterogeneous network, how to enable a user to use a most proper access network at a proper time in a proper place to obtain optimal network application experience is most concerned by people.
Currently, in the conventional art, an access network is selected for a user mostly based on only a current network load status of an area in which the user is located, and an implementation process may be briefly described as follows: First, a WLAN and a cellular network reports their respective network load statuses to an ANDSF (Access Network Discovery and Selection Function) server; then, the ANDSF server configures, with reference to a load status of each network, a policy for connecting a user terminal to a network, that is, an ISMP (Inter-system Mobility Policy) or an ISRP (Inter-system Routing Policy). However, this process may cause the following problems: for example, when load of the cellular network is relatively low, the terminal is controlled to access the cellular network, and if there is still traffic remaining in a traffic package subscribed to by the user, no extra fee is incurred when the terminal access the cellular network; and if the traffic package subscribed to by the user is used up, and the network load status does not change, when the terminal assesses the cellular network, extra expenses are brought to the user.
It can be learned that, in the conventional art, an access network is determined according to a single basis, and a processing process is simple, which cannot ensure properness of selecting an access network for a terminal.